Thread-controlling device for sewing-machines



P. A. HERB. THREAD CONTROLLING DEVICE FOR SEWING.MACHINES.

APPLICATION FILED JULY 27 I9I8.

Patented July 19, 1921.

I I I II IIIII I M I INVENTOR WITNESSES a w-W- I B P. A. HERR.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JULY 27,1918- 48. I Patented July 19,1921.

4 SHEETS-SHEET 2.

Z 1 L 2/ "M INVENTOR N I N mum-Mm W ATTORNEY P. A. HERR- THREADCONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JULY 27, 1918.

Patented July 19, 1921.

4 SHEElS-SHEET a.

m ssw mw T0 TAKEUP N ml====7 m WITNESSES ATTORNEY P. A. HERR.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED IULY 27.1918.- 1,385,048, Patented July 19, 1921.

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S E S E N W W.

PARK A. HERB, OF HILLSIDE, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFAC-TURING COIHPILN'Y, A CGRPORATION OF NEW JERSEY.

THREAD-GONTROLLIN DEVICE FOR SEWINGJJIACHINES.

Application filed July 27,

T0 aZZ whom it may concern.-

Be it known that I, PARK A. HERB, a citizen of the United States,residing at Hillside, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in ThreadControllingDevices for Sewing-Machines, of which the following is a specification,reference being had therein to the accompanying drawings.

This invention relates'to thread-controlling devices for sewing machines01" that type in which the needle is vibrated laterally to producezigzag stitches. In machines of this type heretofore constructed andparticularly those in which the vibratory movements of the needleproduced a seam of extreme width, difficulty was experienced incontrolling the under thread so asto properly position it for thetake-up action and secure its concatenation with the needle-threadin theproper position within the material.

The invention has for its object the construction of athread-controlling device whereby that portion of the under thread to bedrawn into the work will always be positioned in substantial a-linementwith the prospective needle-puncture regardless of the relation to theprevious stitch of the tl1readcase supplying such lower thread, so thatthe upperthread loop shall be subjected below the work in the stitchsetting action to a direct pull without appreciable deflection fromalinenient with the needlepuncture. V

The device herein shown applied to the machine forming the subject oi myprior Patent No. 1,329,763, issued February 3,1920, and constitutes animprovement upon the under thread pull-off and positioning devicedisclosed in my said patent.

It comprises a thread-positioning element sustained for movement uponthe under side of the throat-plate and actuated by a connection with acrank-arm secured to the lower end of a vertically disposed rock-shaftsuitably journaled uponthe upright portion of the sewing machinebracket--arm. Near the upper end of the-rock-shaft is secured a secondcrank-arm to which'is pivotally attached one end of a link whose otherend is adjustably secured to a segment-arm of a rocking member journaledupon the sewing machine bracket-arm. The rocking member is provided witha second arm operatively Specification of Letters Patent. 7

Patented July 19, 1921. 1913'. Serial No. 246,984.

connected with a cam-disk suitably journaled upon the sewing machinebracket-arm and driven from the main-shaft of the ma chine, wherebyoperative movements are im parted to the thread-positioning element.This cam-disk is also utilized for imparting vibratory movements to theneedle-bar sup porting frame as well as bodily movements to theloop-taker to permit the one to cooperate with the other in making awidethrow zigzag seam. The adjustable connection between the link andthe segment-arm permit variation in the throw of the thread positioningelement to correspond with the variations in the vibrations or throw ofthe needle.

.The preferred form of the invention is shown in the accompanyingdrawings in which Figure l'is a rear side elevation of a machineembodying the present improve ment; Fig.2 a top plan and Fig. 3 a bottomplan view of the machine showing the mech anism for actuating the threadpositioning element; Fig. l is a side elevation, partly in section,showing the upper and under threads concatenated at the extreme righthand line of needle-punctures (Z, the needle having risen to its highestposition and moved to the left in line with the needlepuncture c. Fig. 5is a similar side elevation showing the needle descending in line withthe needle-puncture c with the under thread deflected in the samedirection. Fig. 5 is a detail sectional elevation showing the positionof the upper and under thread loops during the final portion of thetake-up action. Fig. 6 is a bottom plan view of the throat-plate,feed-dog and threadengaging element, Fig. 7 is a sectional elevation ofthe same parts taken through the line 02-50, Fig. 6' and Fig. 8illustrates a portion of a seam made by the machine of the presentimprovement.

' The sewing machine embodying the present improvement comprises thework-supporting bed 1 from which rises the hollow standard 2 with thetubular overhanging arm 3 provided with head 4. The mainshaft 5 extendslengthwise within the overhanging arm and is provided at one end withthe balance-wheel 6 provided with grooved belt-wheel 7 while the otherend of the shaft has fixed thereon the cam-disk 8 for impartingoperative movements to the needle-bar 9 carrying the needle 10 and alsofor actuating the stitch-setting means or take-up 11 in a well-knownmanner. Journaled in the head a is the usual springpressed presser -bar12 provided with the presser-foot 13.

Opposed to the presser-foot is the feeddog 14L supported by the feedingframe 15 which receives reciprocatory feeding movements from the feedrock-shaft 16 actuated from the main-shaft 5 by means including a pitman17 pivotally connected to a crankarm 18 of the feed-rock-shaft 16.Rising and falling movements are imparted to the feed-dog by means ofthe feed-lift rockshaft 19 having at one end an arm 20 operativelyconnected with the feed-bar frame 15 while near its other end therock-shaft is provided with a yoke 21 embracing and re ceiving motionfrom the eccentric 22 carried bythe rock-shaft 23 journaled in bearingbosses depending from the work-supporting bed 1. The rock-shaft 23 isactuated from the main-shaft 5 by means including the pitman 21, arocker 25, link 26 and crank-arm 27 in the well known nianner.

The needle-bar 9 is fitted to reciprocate within a pair of verticalsleeves 28, one of which is shown in Fig. 4, each sleeve being carriedat the end of a rod 29 adapted to slide within suitable apertures formedin the head 1. Vibratory movements are imparted to the needle-bar fromthe cam-disk 29, secured upon a cross-shaft 30 suitably journaled uponthe bracketarm and driven by gearing from the main-shaft 5'. The disk 29is provided with a cam-groove 31 entered by a roller-stud 32 carried bythe swinging segment-lever 33 'which lever is embraced by theclamp-block 3 1 adjustably secured thereon by the screw-stud 35. Theclamp-block has pivotally secured thereon one end of a link 36 whoseother end is operatively connected with the rocker 37 j ournaled uponthe cross-shaft 38 carried by the standard 2. The upper end of therocker 37 has a link connection 39 with a crankarm to of a verticallydisposed rock-shaft 11 provided with a second crank-arm 12 having a linkconnection 13 with the needlebar sleeve 28. a

Opposed to the needle and adapted to cooperate with it inthe formationof stitches is the lower thread mechanism. It coinprises the loop-taker,shown in the form of a shuttle let, whose field of action is crosswiseof the line of seam, containing the thread-case 45 and actuated by thedriver 46 carried by the-cross-shaft 47 and suitably driven by bevelgears 4.7, shaft 18 and gears 419 and 50, the latter of which is securedto the oscillating rock-shaft 23. The loop taker is suitably journaledfor oscillatory movement in a raceway formed in the carrying frame 51mounted to slide upon abar 52 suitably supported upon the under side ofthe work-supporting bed 1. The looptaker 44 with its supporting frame 51receives bodily movementsby means of a link 53 one end of which ispivotally connected with the frame 51 by the screw-stud 54: while itsother end is operatively connected tothe lower end of rocker 37 by thescrew-stud 55. Recessed in the work-supporting bed 1 is the usualthroat-plate '56 secured to the bed by the screws 57, the throat-platebeing provided with suitable apertures 58 through which project thetoothed work-engaging portions of the feed-dog 14;. The throatplate isalso provided with the elongated needle-aperture 59 to receive thevibratory needle 10. A supplementary throat-plate 60 is provided toclose the opening in the worksupporting bed 1 so as to make it flushwith the. main throat-plate 56.

From the foregoing it will be readily understood that vibratorymovements are imparted by the cam disk 29 to both the needle 10 and theloop-taker or shuttle 4: 1, the two performing lateral movements inunison in the production of a zigzag seam, the amplitude of lateralthrow of the needle and the loop-taker being determined by suitableadjustment of the position of the clamp-block 34 upon the segment-lever33. The mechanism for actuating the needle and loop-taker t justdescribed is all substantially like that Vshrown in my patent abovereferred to.

In the operation of the machine which, in the present instance, producesa fourstitch zigzag seam, the needle 10 makes four descents throughtherinaterial m before reversal of its direction of vibration, asclearly shown in Figs. 1 and 5. In order to make a zigzag seam of theextreme width of two and one-half inchesor more for which the machine ofthe present improvement has been especially constructed it is importantthat special means be devised to draw ofif and 7 control the underthread so that when the take-up 11 acts to set the stitch the portion ofthe under thread to be concatenated with the upper-thread loop will bedisposed in substantial alinenient with the needle-puncture just maderegardless of the lateral position of the needle. 1

To this end, the under side of the throatplate 56 is formed with achannel 61 adapted to receive and guide the thread-positioning element62 in the shape of a flat bar.

provided with a thread aperture 63 near one end. The thread-positioningelement is retained in its channel by means of a cap-plate 6 1 securedin position by the screws 65. To impart the desired operative movementsto the thread-positioning element 62, its thickened end 66 is rigidlysecured to a sliderod 67 by a screw-stud 68 the other end of theslide-rod having pivotally attached thereto by the screw-stud 69 one endof a link 7 0 whose other end is connected by the pivot screw 71 with,the cranlearm 72 secured to the lower end of the vertically disposedrock-shaft 73 suitably journaled in bearing bosses 741 at the side ofthe standard 2. The upper end of the rock-shaft 73 has rigidly securedthereto a crank-arm 'Z' 5 connected by a screw-stud 76 with one end of alinlr77 whose other end is provided with a screw-bolt 78 whose headenters the guideway T9 formed in the segment-arm 80 of the rocker 81.The rocker is secured upon a bearing stud 82 journaled in the boss 83upon the bracket-arm 3. The rocker is also provided with a second arm8-1 having a roller-stud S5 entering a cam-gro0ve 86 formed upon thecam-disk 29. It will be understood that through the connections justdescribed the movements of the thread-engaging element 62 are maintainedin timed relation with the lateral jogging movements of the needle 10and the loop-taker 44, all of these parts deriving operative movementsfrom the cam-disk 29. It will be observed that the thread positioningelement 62 is actuated entirely independently of the lower threadhandling mechanism.

As represented in Figs. at and 5 the fourstitch zigzag seam, comprisingstitches at the punctures a, b, c and (Z, has been completed and theneedle 10 has moved suliiciently to the left to again enter the materialm in line with the puncture 0 the material having in the meantime beenadvanced by the feeding mechanism. In this position of the parts, theunder thread extends in a substantially straight line from its source ofsupply in the loop-taker to the position where it is last locked withthe needle-thread within the material at the previously formed stitch inthe puncture (Z. As the needle performs its lateral movement preparatoryto its next. descent the thread positioning ele ment 62 has drawn offand moved the under thread to the left, as clearly shown in Fig. 5, orin a direction toward the needle-puncture about to be formed at a, sothat when the loop-taker has passed through the loop of needle-thread,the under thread will occupy a position favorable for the take-upaction. As the take-up begins to draw up the slack needle-thread it willreadily slide along the lower thread until both upper and lower threadsare securely locked in the material at the puncture 0.

After the setting of the stitch at c the needle 10 and loop-taker 41-4:continue their movement to the left to form successive stitches in linewith the punctures at 7) and a, the thread positioning element 62 movingcorrespondingly to draw oil and deflect the lower thread to a positionfavo able for the take-up action.

When the stitch has been set in line with the puncture a, the needle andloop-taker begin to retrace their movements to the right thread to theto form successive stitches in line with punctures Z), c and (Z, thethread-positioning clement following such lateral movements so as todraw off and position the lower right and favorably to the take-upaction, as in the formationof the previous stitches of the zigzag seam.

Having thus set forth the nature of the invention, what I claim hereinis- 1. In alock stitch sewing machine, in combination, upper threadmechanism including a reciprocating needle, cooperating lower-threadmechanism including a looptaker, means for producing relative joggingmovements between both needle and looptaker and the work, means engagingthe lower thread leading from the last stitch to position the same insubstantial alinement with the location of the succeeding stitch ineither direction, and means acting upon the upper thread for setting thestitch.

2. In a lock stitch sewing machine, in combination, upper threadmechanism including a reciprocating needle, cooperating lower threadmechanism including a looptaker whose field of action is crosswise ofthe line of seam, means for producing relative jogging movements betweenboth needle and loop-taker and the work, means engaging the lower threadleading from the last stitch to position the same in substantialalinement with the location of the succeed ing stitch in eitherdirection, and means acting upon the upper thread for setting thestitch.

3. In a sewing machine, in combination, upper thread mechanism includinga reciprocating needle, cooperating lower thread mechanism including aloop-taker, a mainshaft, an actuating element thereon, connec tions withsaid actuating element for imparting lateral movements to the needle andloop-taker, a thread positioning element for drawing oti" lower thread,and connections with said shaft, independent of the firstnamedconnections, for imparting to the threadpositioning element movementssimilar to and in timed relation with those of the needle andloop-taker.

a. In a sewing machine, in combination, upper thread mechanism includinga reciprocating needle, cooperating lower thread mechanism including aloop-taker, a mainshaft, an actuating element thereon, connections withsaid actuating element for imparting lateral movements to the needle andloop-taker, a thread positioning element for drawing oft lower thread, aconnection with said shaft, independent of the first-named connections,for imparting to the thread positioning elements movements similar toand in timed relation. with those of the needle and loop-taker, andmeans for adjusting the amplitude of movement of said thread drawingelement.

"mechanism including a '5. In a sewing machine, in combination, upperthreadrmechanism including a reciprocating needle, cooperating lowerthread loop-taker, a mainshaft, means actuated by said main-shaft forimparting to said needle and loop-taker lateral movements, a rock-shaftoperatively connected with the main-shaft, a thread p0- sitioningelement adapted lateral movements of the needle and looptaker, and aconnection between said rockshaft and thread positioning element forimparting operative movements to thelatter. Intestimony whereof, I havesigned my name to this specification. V V

PARK A, HERE.

to partake of the

